The simplest answer is that it’s not so simple (as usually is the case with biochemistry). Without giving a 1hr biochem lecture, lets see what I can do.
You’re correct in that once absorbed, fructose is taken to the liver for processing. Once there, it’s incorporated into glycolytic pathways after regulatory steps (namely, it enters as fructose 1 phosphate). BUT the author of your article took a very complex topic and screwed it up in its simplification.
By bypassing regulatory steps, you’re not at all comitted to the production of fats. The fructose 1 phosphate can very easily be split into a DHAP and a glyceraldehyde (which then gets phosphorylated to form glyceraldehyde 3 phosphate). These 2 substrates then feed nicely into glycolysis and carb metabolism to be either stored as glycogen or sent to the kreb’s cycle for oxidation (it’s burnt up).
Now, this process is energy costly (requires alot of extra ATP) so that is why huge doses of fructose may affect liver function (from detoxification to blood lipoprotein alterations), but we’re talking 80, 90, 100 grams of pure fructose in a sitting.
There is another consideration that my labmate Eric Noreen and I have discussed. High fructose and glucose combined might be a no-no for fat gain and blood lipids. Since high glucose can promote the upregulation of the fat synthesis machinery and increased production of free fatty acids (FFA’s are made from extra acetylCoA in the kreb’s cycle), by adding fructose at this time the DHAP or glyceraldehyde could actually provide substrates for fat production. You see the glyceraldehyde can form glycerol and glycerol can combine with fatty acids already present (from excess acetyl coA). This makes a triglyceride that can be shipped out to the cells.
BUT REMEMBER!!! THIS HAPPENS WITH HIGH GLUCOSE TOO!!! Bottom line…do not eat huge amounts of fructose (>30g per meal is a safe bet) and do not eat alot of glucose and fructose together. The worst foods are sweetened with high fructose corn syrup and other sugars. These are the villans. Fruits and the bit of fructose in GROW are not!!!